# Copyright 2012-2013 NEC Corporation.  All rights reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

from neutron.agent import securitygroups_rpc as sg_rpc
from neutron.api import extensions as neutron_extensions
from neutron.api.rpc.agentnotifiers import dhcp_rpc_agent_api
from neutron.api.rpc.handlers import dhcp_rpc
from neutron.api.rpc.handlers import l3_rpc
from neutron.api.rpc.handlers import securitygroups_rpc
from neutron.api.v2 import attributes as attrs
from neutron.common import constants as const
from neutron.common import exceptions as n_exc
from neutron.common import rpc as n_rpc
from neutron.common import topics
from neutron.db import agents_db
from neutron.db import agentschedulers_db
from neutron.db import allowedaddresspairs_db as addr_pair_db
from neutron.db import db_base_plugin_v2
from neutron.db import external_net_db
from neutron.db import portbindings_base
from neutron.db import portbindings_db
from neutron.db import quota_db  # noqa
from neutron.db import securitygroups_rpc_base as sg_db_rpc
from neutron.extensions import allowedaddresspairs as addr_pair
from neutron.extensions import portbindings
from neutron.openstack.common import excutils
from neutron.openstack.common import importutils
from neutron.openstack.common import log as logging
from neutron.openstack.common import uuidutils
from neutron.plugins.common import constants as svc_constants
from neutron.plugins.nec.common import config
from neutron.plugins.nec.common import exceptions as nexc
from neutron.plugins.nec.common import utils as necutils
from neutron.plugins.nec.db import api as ndb
from neutron.plugins.nec.db import router as rdb
from neutron.plugins.nec import extensions
from neutron.plugins.nec import nec_router
from neutron.plugins.nec import ofc_manager
from neutron.plugins.nec import packet_filter

LOG = logging.getLogger(__name__)


class SecurityGroupServerRpcMixin(sg_db_rpc.SecurityGroupServerRpcMixin):

    @staticmethod
    def get_port_from_device(device):
        port = ndb.get_port_from_device(device)
        if port:
            port['device'] = device
        LOG.debug("NECPluginV2.get_port_from_device() called, "
                  "device=%(device)s => %(ret)s.",
                  {'device': device, 'ret': port})
        return port


class NECPluginV2(db_base_plugin_v2.NeutronDbPluginV2,
                  external_net_db.External_net_db_mixin,
                  nec_router.RouterMixin,
                  SecurityGroupServerRpcMixin,
                  agentschedulers_db.DhcpAgentSchedulerDbMixin,
                  nec_router.L3AgentSchedulerDbMixin,
                  packet_filter.PacketFilterMixin,
                  portbindings_db.PortBindingMixin,
                  addr_pair_db.AllowedAddressPairsMixin):
    """NECPluginV2 controls an OpenFlow Controller.

    The Neutron NECPluginV2 maps L2 logical networks to L2 virtualized networks
    on an OpenFlow enabled network.  An OpenFlow Controller (OFC) provides
    L2 network isolation without VLAN and this plugin controls the OFC.

    NOTE: This is for Neutron API V2.  Codes for V1.0 and V1.1 are available
          at https://github.com/nec-openstack/neutron-openflow-plugin .

    The port binding extension enables an external application relay
    information to and from the plugin.
    """
    _supported_extension_aliases = ["agent",
                                    "allowed-address-pairs",
                                    "binding",
                                    "dhcp_agent_scheduler",
                                    "external-net",
                                    "ext-gw-mode",
                                    "extraroute",
                                    "l3_agent_scheduler",
                                    "packet-filter",
                                    "quotas",
                                    "router",
                                    "router_provider",
                                    "security-group",
                                    ]

    @property
    def supported_extension_aliases(self):
        if not hasattr(self, '_aliases'):
            aliases = self._supported_extension_aliases[:]
            sg_rpc.disable_security_group_extension_by_config(aliases)
            self.remove_packet_filter_extension_if_disabled(aliases)
            self._aliases = aliases
        return self._aliases

    def __init__(self):
        super(NECPluginV2, self).__init__()
        self.ofc = ofc_manager.OFCManager(self.safe_reference)
        self.base_binding_dict = self._get_base_binding_dict()
        portbindings_base.register_port_dict_function()

        neutron_extensions.append_api_extensions_path(extensions.__path__)

        self.setup_rpc()
        self.l3_rpc_notifier = nec_router.L3AgentNotifyAPI()

        self.network_scheduler = importutils.import_object(
            config.CONF.network_scheduler_driver
        )
        self.router_scheduler = importutils.import_object(
            config.CONF.router_scheduler_driver
        )

        nec_router.load_driver(self.safe_reference, self.ofc)
        self.port_handlers = {
            'create': {
                const.DEVICE_OWNER_ROUTER_GW: self.create_router_port,
                const.DEVICE_OWNER_ROUTER_INTF: self.create_router_port,
                'default': self.activate_port_if_ready,
            },
            'delete': {
                const.DEVICE_OWNER_ROUTER_GW: self.delete_router_port,
                const.DEVICE_OWNER_ROUTER_INTF: self.delete_router_port,
                'default': self.deactivate_port,
            }
        }

    def setup_rpc(self):
        self.service_topics = {svc_constants.CORE: topics.PLUGIN,
                               svc_constants.L3_ROUTER_NAT: topics.L3PLUGIN}
        self.conn = n_rpc.create_connection(new=True)
        self.notifier = NECPluginV2AgentNotifierApi(topics.AGENT)
        self.agent_notifiers[const.AGENT_TYPE_DHCP] = (
            dhcp_rpc_agent_api.DhcpAgentNotifyAPI()
        )
        self.agent_notifiers[const.AGENT_TYPE_L3] = (
            nec_router.L3AgentNotifyAPI()
        )

        # NOTE: callback_sg is referred to from the sg unit test.
        self.callback_sg = securitygroups_rpc.SecurityGroupServerRpcCallback()
        self.endpoints = [
            NECPluginV2RPCCallbacks(self.safe_reference),
            dhcp_rpc.DhcpRpcCallback(),
            l3_rpc.L3RpcCallback(),
            self.callback_sg,
            agents_db.AgentExtRpcCallback()]
        for svc_topic in self.service_topics.values():
            self.conn.create_consumer(svc_topic, self.endpoints, fanout=False)
        # Consume from all consumers in threads
        self.conn.consume_in_threads()

    def _update_resource_status(self, context, resource, id, status):
        """Update status of specified resource."""
        request = {'status': status}
        obj_getter = getattr(self, '_get_%s' % resource)
        with context.session.begin(subtransactions=True):
            obj_db = obj_getter(context, id)
            obj_db.update(request)

    def _update_resource_status_if_changed(self, context, resource_type,
                                           resource_dict, new_status):
        if resource_dict['status'] != new_status:
            self._update_resource_status(context, resource_type,
                                         resource_dict['id'],
                                         new_status)
            resource_dict['status'] = new_status

    def _check_ofc_tenant_in_use(self, context, tenant_id):
        """Check if the specified tenant is used."""
        # All networks are created on OFC
        filters = {'tenant_id': [tenant_id]}
        if self.get_networks_count(context, filters=filters):
            return True
        if rdb.get_router_count_by_provider(context.session,
                                            nec_router.PROVIDER_OPENFLOW,
                                            tenant_id):
            return True
        return False

    def _cleanup_ofc_tenant(self, context, tenant_id):
        if not self._check_ofc_tenant_in_use(context, tenant_id):
            try:
                if self.ofc.exists_ofc_tenant(context, tenant_id):
                    self.ofc.delete_ofc_tenant(context, tenant_id)
                else:
                    LOG.debug(_('_cleanup_ofc_tenant: No OFC tenant for %s'),
                              tenant_id)
            except (nexc.OFCException, nexc.OFCMappingNotFound) as exc:
                reason = _("delete_ofc_tenant() failed due to %s") % exc
                LOG.warn(reason)

    def activate_port_if_ready(self, context, port, network=None):
        """Activate port by creating port on OFC if ready.

        Conditions to activate port on OFC are:
            * port admin_state is UP
            * network admin_state is UP
            * portinfo are available (to identify port on OFC)
        """
        if not network:
            network = super(NECPluginV2, self).get_network(context,
                                                           port['network_id'])

        if not port['admin_state_up']:
            LOG.debug(_("activate_port_if_ready(): skip, "
                        "port.admin_state_up is False."))
            return port
        elif not network['admin_state_up']:
            LOG.debug(_("activate_port_if_ready(): skip, "
                        "network.admin_state_up is False."))
            return port
        elif not ndb.get_portinfo(context.session, port['id']):
            LOG.debug(_("activate_port_if_ready(): skip, "
                        "no portinfo for this port."))
            return port
        elif self.ofc.exists_ofc_port(context, port['id']):
            LOG.debug(_("activate_port_if_ready(): skip, "
                        "ofc_port already exists."))
            return port

        try:
            self.ofc.create_ofc_port(context, port['id'], port)
            port_status = const.PORT_STATUS_ACTIVE
        except (nexc.OFCException, nexc.OFCMappingNotFound) as exc:
            LOG.error(_("create_ofc_port() failed due to %s"), exc)
            port_status = const.PORT_STATUS_ERROR

        if port_status != port['status']:
            self._update_resource_status(context, "port", port['id'],
                                         port_status)
            port['status'] = port_status

        return port

    def deactivate_port(self, context, port, raise_exc=True):
        """Deactivate port by deleting port from OFC if exists."""
        if not self.ofc.exists_ofc_port(context, port['id']):
            LOG.debug(_("deactivate_port(): skip, ofc_port for port=%s "
                        "does not exist."), port['id'])
            return port

        try:
            self.ofc.delete_ofc_port(context, port['id'], port)
            self._update_resource_status_if_changed(
                context, "port", port, const.PORT_STATUS_DOWN)
            return port
        except (nexc.OFCResourceNotFound, nexc.OFCMappingNotFound):
            # There is a case where multiple delete_port operation are
            # running concurrently. For example, delete_port from
            # release_dhcp_port and deletion of network owned ports in
            # delete_network. In such cases delete_ofc_port may receive
            # 404 error from OFC.
            # Also there is a case where neutron port is deleted
            # between exists_ofc_port and get_ofc_id in delete_ofc_port.
            # In this case OFCMappingNotFound is raised.
            # These two cases are valid situations.
            LOG.info(_("deactivate_port(): OFC port for port=%s is "
                       "already removed."), port['id'])
            # The port is already removed, so there is no need
            # to update status in the database.
            port['status'] = const.PORT_STATUS_DOWN
            return port
        except nexc.OFCException as exc:
            with excutils.save_and_reraise_exception() as ctxt:
                LOG.error(_("Failed to delete port=%(port)s from OFC: "
                            "%(exc)s"), {'port': port['id'], 'exc': exc})
                self._update_resource_status_if_changed(
                    context, "port", port, const.PORT_STATUS_ERROR)
                if not raise_exc:
                    ctxt.reraise = False
                    return port

    def _net_status(self, network):
        # NOTE: NEC Plugin accept admin_state_up. When it's False, this plugin
        # deactivate all ports on the network to drop all packet and show
        # status='DOWN' to users. But the network is kept defined on OFC.
        if network['network']['admin_state_up']:
            return const.NET_STATUS_ACTIVE
        else:
            return const.NET_STATUS_DOWN

    def create_network(self, context, network):
        """Create a new network entry on DB, and create it on OFC."""
        LOG.debug(_("NECPluginV2.create_network() called, "
                    "network=%s ."), network)
        tenant_id = self._get_tenant_id_for_create(context, network['network'])
        net_name = network['network']['name']
        net_id = uuidutils.generate_uuid()

        #set up default security groups
        self._ensure_default_security_group(context, tenant_id)

        network['network']['id'] = net_id
        network['network']['status'] = self._net_status(network)

        try:
            if not self.ofc.exists_ofc_tenant(context, tenant_id):
                self.ofc.create_ofc_tenant(context, tenant_id)
            self.ofc.create_ofc_network(context, tenant_id, net_id, net_name)
        except (nexc.OFCException, nexc.OFCMappingNotFound) as exc:
            LOG.error(_("Failed to create network id=%(id)s on "
                        "OFC: %(exc)s"), {'id': net_id, 'exc': exc})
            network['network']['status'] = const.NET_STATUS_ERROR

        with context.session.begin(subtransactions=True):
            new_net = super(NECPluginV2, self).create_network(context, network)
            self._process_l3_create(context, new_net, network['network'])

        return new_net

    def update_network(self, context, id, network):
        """Update network and handle resources associated with the network.

        Update network entry on DB. If 'admin_state_up' was changed, activate
        or deactivate ports and packetfilters associated with the network.
        """
        LOG.debug(_("NECPluginV2.update_network() called, "
                    "id=%(id)s network=%(network)s ."),
                  {'id': id, 'network': network})

        if 'admin_state_up' in network['network']:
            network['network']['status'] = self._net_status(network)

        session = context.session
        with session.begin(subtransactions=True):
            old_net = super(NECPluginV2, self).get_network(context, id)
            new_net = super(NECPluginV2, self).update_network(context, id,
                                                              network)
            self._process_l3_update(context, new_net, network['network'])

        changed = (old_net['admin_state_up'] != new_net['admin_state_up'])
        if changed and not new_net['admin_state_up']:
            # disable all active ports of the network
            filters = dict(network_id=[id], status=[const.PORT_STATUS_ACTIVE])
            ports = super(NECPluginV2, self).get_ports(context,
                                                       filters=filters)
            for port in ports:
                # If some error occurs, status of errored port is set to ERROR.
                # This is avoids too many rollback.
                # TODO(amotoki): Raise an exception after all port operations
                # are finished to inform the caller of API of the failure.
                self.deactivate_port(context, port, raise_exc=False)
        elif changed and new_net['admin_state_up']:
            # enable ports of the network
            filters = dict(network_id=[id], status=[const.PORT_STATUS_DOWN],
                           admin_state_up=[True])
            ports = super(NECPluginV2, self).get_ports(context,
                                                       filters=filters)
            for port in ports:
                self.activate_port_if_ready(context, port, new_net)

        return new_net

    def delete_network(self, context, id):
        """Delete network and packet_filters associated with the network.

        Delete network entry from DB and OFC. Then delete packet_filters
        associated with the network. If the network is the last resource
        of the tenant, delete unnessary ofc_tenant.
        """
        LOG.debug(_("NECPluginV2.delete_network() called, id=%s ."), id)
        net_db = self._get_network(context, id)
        tenant_id = net_db['tenant_id']
        ports = self.get_ports(context, filters={'network_id': [id]})

        # check if there are any tenant owned ports in-use;
        # consider ports owned by floating ips as auto_delete as if there are
        # no other tenant owned ports, those floating ips are disassociated
        # and will be auto deleted with self._process_l3_delete()
        only_auto_del = all(p['device_owner'] in
                            db_base_plugin_v2.AUTO_DELETE_PORT_OWNERS or
                            p['device_owner'] == const.DEVICE_OWNER_FLOATINGIP
                            for p in ports)
        if not only_auto_del:
            raise n_exc.NetworkInUse(net_id=id)

        self._process_l3_delete(context, id)

        # Make sure auto-delete ports on OFC are deleted.
        # If an error occurs during port deletion,
        # delete_network will be aborted.
        for port in [p for p in ports if p['device_owner']
                     in db_base_plugin_v2.AUTO_DELETE_PORT_OWNERS]:
            port = self.deactivate_port(context, port)

        # delete all packet_filters of the network from the controller
        for pf in net_db.packetfilters:
            self.delete_packet_filter(context, pf['id'])

        if self.ofc.exists_ofc_network(context, id):
            try:
                self.ofc.delete_ofc_network(context, id, net_db)
            except (nexc.OFCException, nexc.OFCMappingNotFound) as exc:
                with excutils.save_and_reraise_exception():
                    reason = _("delete_network() failed due to %s") % exc
                    LOG.error(reason)
                    self._update_resource_status(
                        context, "network", net_db['id'],
                        const.NET_STATUS_ERROR)

        super(NECPluginV2, self).delete_network(context, id)

        self._cleanup_ofc_tenant(context, tenant_id)

    def _get_base_binding_dict(self):
        sg_enabled = sg_rpc.is_firewall_enabled()
        vif_details = {portbindings.CAP_PORT_FILTER: sg_enabled,
                       portbindings.OVS_HYBRID_PLUG: sg_enabled}
        binding = {portbindings.VIF_TYPE: portbindings.VIF_TYPE_OVS,
                   portbindings.VIF_DETAILS: vif_details}
        return binding

    def _extend_port_dict_binding_portinfo(self, port_res, portinfo):
        if portinfo:
            port_res[portbindings.PROFILE] = {
                'datapath_id': portinfo['datapath_id'],
                'port_no': portinfo['port_no'],
            }
        elif portbindings.PROFILE in port_res:
            del port_res[portbindings.PROFILE]

    def _validate_portinfo(self, profile):
        key_specs = {
            'datapath_id': {'type:string': None, 'required': True},
            'port_no': {'type:non_negative': None, 'required': True,
                        'convert_to': attrs.convert_to_int}
        }
        msg = attrs._validate_dict_or_empty(profile, key_specs=key_specs)
        if msg:
            raise n_exc.InvalidInput(error_message=msg)

        datapath_id = profile.get('datapath_id')
        port_no = profile.get('port_no')
        try:
            dpid = int(datapath_id, 16)
        except ValueError:
            raise nexc.ProfilePortInfoInvalidDataPathId()
        if dpid > 0xffffffffffffffffL:
            raise nexc.ProfilePortInfoInvalidDataPathId()
        # Make sure dpid is a hex string beginning with 0x.
        dpid = hex(dpid)

        if int(port_no) > 65535:
            raise nexc.ProfilePortInfoInvalidPortNo()

        return {'datapath_id': dpid, 'port_no': port_no}

    def _process_portbindings_portinfo_create(self, context, port_data, port):
        """Add portinfo according to bindings:profile in create_port().

        :param context: neutron api request context
        :param port_data: port attributes passed in PUT request
        :param port: port attributes to be returned
        """
        profile = port_data.get(portbindings.PROFILE)
        # If portbindings.PROFILE is None, unspecified or an empty dict
        # it is regarded that portbinding.PROFILE is not set.
        profile_set = attrs.is_attr_set(profile) and profile
        if profile_set:
            portinfo = self._validate_portinfo(profile)
            portinfo['mac'] = port['mac_address']
            ndb.add_portinfo(context.session, port['id'], **portinfo)
        else:
            portinfo = None
        self._extend_port_dict_binding_portinfo(port, portinfo)

    def _process_portbindings_portinfo_update(self, context, port_data, port):
        """Update portinfo according to bindings:profile in update_port().

        :param context: neutron api request context
        :param port_data: port attributes passed in PUT request
        :param port: port attributes to be returned
        :returns: 'ADD', 'MOD', 'DEL' or None
        """
        if portbindings.PROFILE not in port_data:
            return
        profile = port_data.get(portbindings.PROFILE)
        # If binding:profile is None or an empty dict,
        # it means binding:.profile needs to be cleared.
        # TODO(amotoki): Allow Make None in binding:profile in
        # the API layer. See LP bug #1220011.
        profile_set = attrs.is_attr_set(profile) and profile
        cur_portinfo = ndb.get_portinfo(context.session, port['id'])
        if profile_set:
            portinfo = self._validate_portinfo(profile)
            portinfo_changed = 'ADD'
            if cur_portinfo:
                if (necutils.cmp_dpid(portinfo['datapath_id'],
                                      cur_portinfo.datapath_id) and
                    portinfo['port_no'] == cur_portinfo.port_no):
                    return
                ndb.del_portinfo(context.session, port['id'])
                portinfo_changed = 'MOD'
            portinfo['mac'] = port['mac_address']
            ndb.add_portinfo(context.session, port['id'], **portinfo)
        elif cur_portinfo:
            portinfo_changed = 'DEL'
            portinfo = None
            ndb.del_portinfo(context.session, port['id'])
        else:
            portinfo = None
            portinfo_changed = None
        self._extend_port_dict_binding_portinfo(port, portinfo)
        return portinfo_changed

    def extend_port_dict_binding(self, port_res, port_db):
        super(NECPluginV2, self).extend_port_dict_binding(port_res, port_db)
        self._extend_port_dict_binding_portinfo(port_res, port_db.portinfo)

    def _process_portbindings_create(self, context, port_data, port):
        super(NECPluginV2, self)._process_portbindings_create_and_update(
            context, port_data, port)
        self._process_portbindings_portinfo_create(context, port_data, port)

    def _process_portbindings_update(self, context, port_data, port):
        super(NECPluginV2, self)._process_portbindings_create_and_update(
            context, port_data, port)
        portinfo_changed = self._process_portbindings_portinfo_update(
            context, port_data, port)
        return portinfo_changed

    def _get_port_handler(self, operation, device_owner):
        handlers = self.port_handlers[operation]
        handler = handlers.get(device_owner)
        if handler:
            return handler
        else:
            return handlers['default']

    def create_port(self, context, port):
        """Create a new port entry on DB, then try to activate it."""
        LOG.debug(_("NECPluginV2.create_port() called, port=%s ."), port)

        port['port']['status'] = const.PORT_STATUS_DOWN

        port_data = port['port']
        with context.session.begin(subtransactions=True):
            self._ensure_default_security_group_on_port(context, port)
            sgids = self._get_security_groups_on_port(context, port)
            port = super(NECPluginV2, self).create_port(context, port)
            self._process_portbindings_create(context, port_data, port)
            self._process_port_create_security_group(
                context, port, sgids)
            port[addr_pair.ADDRESS_PAIRS] = (
                self._process_create_allowed_address_pairs(
                    context, port,
                    port_data.get(addr_pair.ADDRESS_PAIRS)))
        self.notify_security_groups_member_updated(context, port)

        handler = self._get_port_handler('create', port['device_owner'])
        return handler(context, port)

    def _update_ofc_port_if_required(self, context, old_port, new_port,
                                     portinfo_changed):
        def get_ofport_exist(port):
            return (port['admin_state_up'] and
                    bool(port.get(portbindings.PROFILE)))

        # Determine it is required to update OFC port
        need_add = False
        need_del = False
        need_packet_filter_update = False

        old_ofport_exist = get_ofport_exist(old_port)
        new_ofport_exist = get_ofport_exist(new_port)

        if old_port['admin_state_up'] != new_port['admin_state_up']:
            if new_port['admin_state_up']:
                need_add |= new_ofport_exist
            else:
                need_del |= old_ofport_exist

        if portinfo_changed:
            if portinfo_changed in ['DEL', 'MOD']:
                need_del |= old_ofport_exist
            if portinfo_changed in ['ADD', 'MOD']:
                need_add |= new_ofport_exist
            need_packet_filter_update |= True

        # Update OFC port if required
        if need_del:
            self.deactivate_port(context, new_port)
            if need_packet_filter_update:
                self.deactivate_packet_filters_by_port(context, id)
        if need_add:
            if need_packet_filter_update:
                self.activate_packet_filters_by_port(context, id)
            self.activate_port_if_ready(context, new_port)

    def update_port(self, context, id, port):
        """Update port, and handle packetfilters associated with the port.

        Update network entry on DB. If admin_state_up was changed, activate
        or deactivate the port and packetfilters associated with it.
        """
        LOG.debug(_("NECPluginV2.update_port() called, "
                    "id=%(id)s port=%(port)s ."),
                  {'id': id, 'port': port})
        need_port_update_notify = False
        with context.session.begin(subtransactions=True):
            old_port = super(NECPluginV2, self).get_port(context, id)
            new_port = super(NECPluginV2, self).update_port(context, id, port)
            portinfo_changed = self._process_portbindings_update(
                context, port['port'], new_port)
            if addr_pair.ADDRESS_PAIRS in port['port']:
                need_port_update_notify |= (
                    self.update_address_pairs_on_port(context, id, port,
                                                      old_port,
                                                      new_port))
            need_port_update_notify |= self.update_security_group_on_port(
                context, id, port, old_port, new_port)

        need_port_update_notify |= self.is_security_group_member_updated(
            context, old_port, new_port)
        if need_port_update_notify:
            self.notifier.port_update(context, new_port)

        self._update_ofc_port_if_required(context, old_port, new_port,
                                          portinfo_changed)
        return new_port

    def delete_port(self, context, id, l3_port_check=True):
        """Delete port and packet_filters associated with the port."""
        LOG.debug(_("NECPluginV2.delete_port() called, id=%s ."), id)
        # ext_sg.SECURITYGROUPS attribute for the port is required
        # since notifier.security_groups_member_updated() need the attribute.
        # Thus we need to call self.get_port() instead of super().get_port()
        port_db = self._get_port(context, id)
        port = self._make_port_dict(port_db)

        handler = self._get_port_handler('delete', port['device_owner'])
        # handler() raises an exception if an error occurs during processing.
        port = handler(context, port)

        # delete all packet_filters of the port from the controller
        for pf in port_db.packetfilters:
            self.delete_packet_filter(context, pf['id'])

        # if needed, check to see if this is a port owned by
        # and l3-router.  If so, we should prevent deletion.
        if l3_port_check:
            self.prevent_l3_port_deletion(context, id)
        with context.session.begin(subtransactions=True):
            router_ids = self.disassociate_floatingips(
                context, id, do_notify=False)
            self._delete_port_security_group_bindings(context, id)
            super(NECPluginV2, self).delete_port(context, id)

        # now that we've left db transaction, we are safe to notify
        self.notify_routers_updated(context, router_ids)
        self.notify_security_groups_member_updated(context, port)


class NECPluginV2AgentNotifierApi(n_rpc.RpcProxy,
                                  sg_rpc.SecurityGroupAgentRpcApiMixin):
    '''RPC API for NEC plugin agent.'''

    BASE_RPC_API_VERSION = '1.0'

    def __init__(self, topic):
        super(NECPluginV2AgentNotifierApi, self).__init__(
            topic=topic, default_version=self.BASE_RPC_API_VERSION)
        self.topic_port_update = topics.get_topic_name(
            topic, topics.PORT, topics.UPDATE)

    def port_update(self, context, port):
        self.fanout_cast(context,
                         self.make_msg('port_update',
                                       port=port),
                         topic=self.topic_port_update)


class NECPluginV2RPCCallbacks(n_rpc.RpcCallback):

    RPC_API_VERSION = '1.0'

    def __init__(self, plugin):
        super(NECPluginV2RPCCallbacks, self).__init__()
        self.plugin = plugin

    def update_ports(self, rpc_context, **kwargs):
        """Update ports' information and activate/deavtivate them.

        Expected input format is:
            {'topic': 'q-agent-notifier',
             'agent_id': 'nec-q-agent.' + <hostname>,
             'datapath_id': <datapath_id of br-int on remote host>,
             'port_added': [<new PortInfo>,...],
             'port_removed': [<removed Port ID>,...]}
        """
        LOG.debug(_("NECPluginV2RPCCallbacks.update_ports() called, "
                    "kwargs=%s ."), kwargs)
        datapath_id = kwargs['datapath_id']
        session = rpc_context.session
        for p in kwargs.get('port_added', []):
            id = p['id']
            portinfo = ndb.get_portinfo(session, id)
            if portinfo:
                if (necutils.cmp_dpid(portinfo.datapath_id, datapath_id) and
                    portinfo.port_no == p['port_no']):
                    LOG.debug(_("update_ports(): ignore unchanged portinfo in "
                                "port_added message (port_id=%s)."), id)
                    continue
                ndb.del_portinfo(session, id)
            port = self._get_port(rpc_context, id)
            if port:
                ndb.add_portinfo(session, id, datapath_id, p['port_no'],
                                 mac=p.get('mac', ''))
                # NOTE: Make sure that packet filters on this port exist while
                # the port is active to avoid unexpected packet transfer.
                if portinfo:
                    self.plugin.deactivate_port(rpc_context, port,
                                                raise_exc=False)
                    self.plugin.deactivate_packet_filters_by_port(
                        rpc_context, id, raise_exc=False)
                self.plugin.activate_packet_filters_by_port(rpc_context, id)
                self.plugin.activate_port_if_ready(rpc_context, port)
        for id in kwargs.get('port_removed', []):
            portinfo = ndb.get_portinfo(session, id)
            if not portinfo:
                LOG.debug(_("update_ports(): ignore port_removed message "
                            "due to portinfo for port_id=%s was not "
                            "registered"), id)
                continue
            if not necutils.cmp_dpid(portinfo.datapath_id, datapath_id):
                LOG.debug(_("update_ports(): ignore port_removed message "
                            "received from different host "
                            "(registered_datapath_id=%(registered)s, "
                            "received_datapath_id=%(received)s)."),
                          {'registered': portinfo.datapath_id,
                           'received': datapath_id})
                continue
            ndb.del_portinfo(session, id)
            port = self._get_port(rpc_context, id)
            if port:
                self.plugin.deactivate_port(rpc_context, port, raise_exc=False)
                self.plugin.deactivate_packet_filters_by_port(
                    rpc_context, id, raise_exc=False)

    def _get_port(self, context, port_id):
        try:
            return self.plugin.get_port(context, port_id)
        except n_exc.PortNotFound:
            return None
